5. Superficial Mycoses Flashcards Preview

Elsevier Mycology (RVSP) > 5. Superficial Mycoses > Flashcards

Flashcards in 5. Superficial Mycoses Deck (30):
1

Superficial mycoses of the skin

Tineas

2

Superficial mycoses of the hair

Piedras

3

Media that specimens for superficial mycoses are inoculated to

SDA

4

Causative agent of Tinea versicolor

Malassezia furfur

5

Superficial infection of the keratinized layers of the skin

Tinea versicolor

6

Specimen for direct examination for tinea versicolor

Skin

7

Direct examination:

KOH will show yeastlike and hyphal forms

M. furfur

8

Lipophilic organism

M. furfur

9

Special culture method for M. furfur

Since it is lipophilic, add an oil overlay to the SDA and incubate at 37°C

10

Microscopic:

Thick-walled hyphae
"Yeast", some budding

M. furfur

11

Microscopic:

Spaghetti and meatballs

M. furfur

12

Causative agent of Tinea nigra

Hortaea werneckii

13

Infection of the keratinized skin layers of the hand

Tinea nigra

14

How many days will H. werneckii mature?

21 days (slow grower)

15

Microscopic:

- Septate, thick-walled hyphae
- Yeastlike conidia
- Chlamydospores
- Annellides present (intercalary and lateral)

H. werneckii

16

Microscopic:

Initially has hyaline hyphae that become olive-colored

H. werneckii

17

Infection of hair of beard and mustache

White piedra

18

Causes white piedra

Trichosporon beigelii

19

Appearance on SDA: yeastlike colonies

T. beigelii

20

Micrscopic: nodule surrounding hair

T. beigelii

21

Macroscopic:

Rapid grower
Yeastlike
Urease production

T. beigelii

22

Microscopic:

- many pseudohyphae and hyphae
- blastoconidia (unicellular, variable in shape)
- arthroconidia

T. beigelii

23

Fungal infection of scalp hair

Black piedra

24

Fungi acquired through swimming in rivers and stagnant waters

Piedraia hortae

25

Causative agent of black piedra

Piedraia hortae

26

Mycosis that forms black, stony, hard nodules on hair

Black piedra caused by Piedraia hortae

27

Optimum growth temperature of Piedraia hortae

25°C (slow grower)

28

Macroscopic:

- Slow growing
- small, folded, dark brown to black
- may produce a reddish-brown diffusible pigment

Piedraia hortae

29

Microscopic:

- Septate, pigmented hyphae
- asci containing 2-8 hyaline banana-shaped ascospores (ellipsoid, solitary, or in clusters)

Piedraia hortae

30

Superficial mycoses infect the _____, _____, and _____.

Hair
Skin
Nails